There have been gunfights outside American schools and a big private university. The mayors of two suburbs have been murdered. And a grenade has been thrown at Saturday evening strollers in a square, injuring 12. All this has happened since August not in Kabul or Baghdad but in Monterrey in northern Mexico. The latest battleground in a multilateral war between drug-trafficking gangs and the authorities, Monterrey is not a dusty outpost. It is one of the biggest industrial cities of North America, a couple of hours’ drive from Texas and home to some of Mexico’s leading companies.

The maelstrom of drug-related violence that is engulfing Mexico has produced exaggerated, sometimes xenophobic, alarm in parts of the United States. The response in Mexico City has, until recently, been defensive denial.

Both reactions are wrong. The violence, in which at least 28,000 people have been killed since 2006, reflects a double failure of public policy: decades of neglect of the basic institutions of the rule of law in Mexico, and a failed approach to drug consumption (plus lax gun laws) in the United States. These mistakes have helped to create the world’s most powerful organised-crime syndicates. Reforms in both countries could help tame them.

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